Abstract

The critically endangered Eremostachys superba Royle ex Benth. Shows almost negligible sexual reproduction under natural conditions (<= 5%) and survives only vegetatively. Investigations on the role of pollination biology in the loss of sexual reproduction revealed a pollinator limitation in the natural habitat. Increased floral attractiveness was provided to counteract this pollinator limitation syndrome by increasing flower density. Observations were made on insect visits and resultant seed set in the ex situ plants and compared with that observed under in situ conditions. Infinite pollinators visited ex situ flowers but affected only 38% seed set, indicating a reduced fertilization due to geitonogamous pollination. These results suggested that lack of sexual reproduction in E. superba was partly due to pollen limitation.

中文摘要

瀕臨絕種的印度沙穗(唇形科)在自然環境下有性繁殖低於 5%，而只以無性繁殖得以存續。經授粉生物學研究，得知自然環境下因授粉者限制了有性繁殖。故增加花的數量以補強授粉者之限制。觀察在原地及移地下比較昆蟲訪問及其結實，發現雖然移地下使昆蟲不斷訪問，卻只結實 38%，表示自株授粉會減低受妊。此係表示印度沙穗欠缺有性繁殖乃部份受到花粉量之限制。 關鍵詞：印度沙穗、有效花粉量、自株授粉、花粉量限制。

Keyword: Eremostachys superba, Effective pollen flow, Geitonogamy, Pollen limitation.